Swivel stacker



F. P. GRAY SWIVEL STACKER Feb. 14, 1961 3 Sheets-Sheet 1 Filed Dec. 19, 1958 mmvroa FRANKL/N R GRAY BY 7 V 7 ATTORNEYS F. P. GRAY SWIVEL STACKER Feb. 14, 1961 3 Sheets-Sheet 2 Filed Dec. 19, 1958 INVENTOR.

FRANKu/v 1. GRAY ATTORNEYS Feb. 14, 1961 F. P. GRAY 2,971,631

SWIVEL STACKER Filed Dec. 19, 1958 5 Sheets-Sheet I5 F/s. 8 a? INVENTOR. FRAg KL/N f. GRAY ATTORNEYS SWIVEL STACKER Franklin P. Gray, 2600 E.-Flota:-Place,-Denve1-, c010.

Filed'Dec fi, iasasenNo. 131,134 :16 Claims. (Cl.'-128--.119

This invention relates to power-driven loaders and,

more -specifically, to a mobile'swivel stacker of a-type *especially suited for use in loading boxes and bags.

"Conveyors-of one type or another are, of course, quite common in industry and they-save countless man hours of hard manual labor. In "general, however, these conveyorsaccomplish only part -of the job as manual labor ;is quite-often required to 'unload'them and transfer the material conveyed 'thereonto, awaiting transportation or storage facilities. Hand-loading "and stacking of bags and cartons from a conveyor is still ;fairly commn, especiallywith lightweight articles. Heavy bags and boxes,

on the other hand, are customarily liftedby hand from viously,-such'an operation is time-consuming, inefiicient,

and oftentimes requires the services of several workmen to perform the unloading andstacking functions,'or both.

,At this point, it would be well to examine afew of the-more important operational and structural characteristics that should be 'present'in a, mechanical device fOfIlSB iH performing'the aiorementioned unloading and stacking functions. First of -all,-s uch ,a unit should be mobile and preferably lightweight so that itcan be moved easily from OIlQPlfiCB'tQ another. Secondly, it should be equipped to swing from side-to-sidein order that a bagor box-carried thereby can be placed on top of-any one of several stacks. Third, a loader for this purpose should be elevatable to adjust to varying stack heights. Fourth,

a stacker of this type should be designed so that it can be retracted underneath the conveyor associated therewith as there will be ocasions when the bags or boxes must he laid on stacks in difierent rows.

A 'few'other important considerations are to provide such 'a machine with simplified controls "whereby the various operative functions can b'e-accornplished simply and rapidly by a single operator. Another is that the device should be adaptable for use with any one of the several-'dilferent'tjypes of conveyors. Also, it should be capable of handling and stacking a wide variety of different types, sizes, weights and shapes of packaged materials. Still another desirable feature in such a unit would be the inclusion of appropriate braking means operative to stop and maintain it in the desired fixed'position.

=Lt is, therefore, the principal object of the present in "vention to-provide a mobile swivel stacker for use with a 2,971,631 Patented Feb, 14,1961

' Still another object is'the provision of a stackerftliat contains a simple controlmechanism operable by one man; yet, which includes a hydraulic elevator and braking mechanism, a power-driven endless belt, a reversible sup porting cariiage, and a manually-operable swivel assembly. I p

An additional objective of the instant invention is 'to provide a swivel-type stacker that is adaptable for'use with any of the conventional conveyors and is capable of handling a wide variety of packaged materials.

Furtherobjects are the provision of a package loader that is relatively inexpensive, versatile, compact, lightweight and rugged.

Other objects 'will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawing thatfollows, and in which:

Figure l'isia topplan view ofthe swivel stacker of the present invention showing it attached to the discharge en of a spring-belt conveyor;

Figurel is a side elevation of the stacker and conveyor showing the elevated position of the endless belt in 'dotted lines;

"Figure 3 is a fragmentary section to an enlarged scale takenalong line 3, 3 of Figure 2;

Figure 4 is a fragmentary section taken along line 4-4 of Figure 3;

Figure 5 is a topplan view showing the three-wheeled caster assembly that supports the stacker carriage with the brake drum assembly removed therefrom; v Figure 6 is an enlarged section taken alongline i6-'- of Figure 2 showing the gear motor-drive for the end- ,less' belt; V .F igure 7,is a fragmentary toppla'n view similar to Figure 1, but to a reduced scale, showing the manneriin which the stacker belt swings in relation to the conveyor; and,-

Figure 8 is a simplified schematic diagram illustrating the major operational components of the assembly and their connections to one another.

Referring now to the drawing, and in particular to Figures 1 and 2 thereof, it will be seen that the swivel stacker of the present invention, which has been indicated generally by numeral'lt), is preferably connected, .orat least closely associated, with a conventional conveyor unit designated in a general way with numeral 12. As shown, the conveyor is of the type having a wheel-supported frame '14 comprising a plurality of hingedly-interconnected sections or segments'16 each of which supports a grooved roller 18 journalled for rotationalmovement thereon about a transverse horizontal axis. .One or more of these rollers is motor-driven by a prime mover which has not been illustrated and the remaining rollers are turned by means of endless spring belts 20 located within the grooves and forming an operative connection therebetween. The discharge end of the conveyor is provided with a pan or chute 22 positioned to direct the packaged materialssupported and conveyed along the endless belts onto the stacker which is preferably connected to the conveyor unit with a suitable detachable towing tongue 24. i

This particular typeof conveyor, although it forms no part of the present invention, is particularly desirable for use with the swivel stacker claimed herein because it can convey materials packaged in paper or cloth bags without danger of their tearing or otherwise becoming damaged. Secondly, the hinged frame construction adapts it quite well to loading and stacking applications when flexibility and mobility are of utmost importance. Also, a unit of this type can be self-propelled to facilitate movement thereof, and of the stacker attached thereto, "from place to place in a warehouse, truck,

' storageor transportation facility,

boxcar or other .32 mounted on the outboard corners at the front end thereof for. swinging; movement about vertical pivot axes. Transverse element 33 located at the rear end of the bedframe carries on the underside thereof at a 'point approximately midway between the ends, the plate 34 of a conventional hydraulically-operated drum-type automobile brake including the brake shoes, spindle bearings and associated fluid lines (not shown). The drum 36 is mounted on the spindle for relative rotational movement encircling the shoes and on the underside of the plate. The rear end of the bedframe is supported on tandem casters 38 attached for pivotalmovement to the under- 'side of caster frame. 40 that is, in turn, fixedly mounted a r on the underside of the brake drum 36. V V Also included as a part of the carriage 28, is an upright frame having substantially vertical sideposts '42 attached to the bedframe and braced by suitable struts .44. The endless belt conveyor assembly 26 is mounted between the upper ends of the sideposts 42 of the upright framefor tiltable movement about a substantially horizontal axis between the full-line and dotted-line positions of Figure 2. Movement of the conveyor assembly relative to the carriage is accomplished by means of a hydraulically-operated cylinder 46 and piston 48 connected between transverse element 50 of the upright frame and 'a similar element 52 on the underside of the conveyor. Hydraulic fluid under pressure is supplied to the cylinder 46 and also to the hydraulic brake system by means of electrically-driven pump 54 carried by transverse elements 56 of the bedframe. A foot-pedal-operated controlsystem, indicated generally by numeral 58, is also carried on the front end of the bedframe, the function of which will be described presently.

" Still with reference to Figures 1 and 2, the endless belt conveyor assembly 26 will be seen to include a generally rectangular roller frame 60 having a drive roller 62 journalled at the front end thereof, a driven roller 64 at the rear end, and a plurality of spaced substantially parallel idling rollers 66 located therebetween. An endless fabric belt 68 encircles the drive and driven rollerspowered by a gear motor 70 or similar-prime mover attached to the underside of the roller frame at the rear end thereof and operatively connected to drive roller 62. the well known manner to a pair of identical on-oif switches 72 mounted on opposite sides of the roller frame at the front end thereof for use in controlling the movement of the conveyor belt.

In Figures 2, 3, 5 and 7, it can be seen that the caster frame 40 includes a rearwardly extending element 74 terminating in a pin 76 having lugs 78 projecting laterally from opposite sides thereof. The conveyor tongue 24,

Gear motor 70 is electrically connected in in the form shown, is attached to the conveyor frame 14 V p for swinging movement about a substantially horizontal axis but it cannot be moved from side-to-side without also swinging the front hinged segment of the frame. The front end of the tongue terminates in a bifurcated latch element 80, the legs of which lap pin 76 of the caster frame and include downwardly opening notches 82 located to receive the lugs 78 in the manner shown in Figures 2 and 3. Thus, caster frame 40 is substantially fixed in relation to the tongue 24, brake drum 36, and the front end segment of the conveyor frame 14. Therefore, with the hydraulic brakes released, the bedframe 30, rear casters 32, upright frame, conveyor assembly 26., disk 34 and associated elements all swing from sideto-side as a unit about the spindle as an axis between the full-line and dotted-line positions of Figure 7 relative to the brake drum 36, caster frame 40, tongue 24 and Such an arrangement enables the swivel stacker to swing from 'side-to-side in relation to the conveyor in order that the packaged materials conveyed thereon may be deposited on any one of several stacks. To facilitate movement of the stacker by the operator, handles 84 are pro vided on opposite sides thereof near the front end as best seen in Figure l. V V,

Figure .6 shows the details of the drive for the endless belt conveyor assembly. The drive roller 62 includes a shaft 86 journalled for rotation within roller bearings 88 carried by the sides of the roller frame 60. Oneend 0f the roller shaft is provided with a sprocket 90 operatively connected by a sprocketchain' to a similar sprocket 92 carried by the gear motor shaft 94a The gear motor 70 may be attached to the underside of the roller frame by any suitable motor-support bracket 96.

Finally, with reference to Figures 1, 2 and 8 of the drawing, the control system for the several functional units of the loader will be described. It has already been mentioned that elements 72 located on the sides of the endless belt conveyor assembly 26 comprise ou-oif switches electrically connected to gear motor 70 and operative to start and stop endless fabric belt 68. Similarly, switch 98 mounted on the carriage by the hydraulic cylinder is an on-off switch operative upon actuation to start and stop electric pump 54. This pump is controlled erably connected between the solenoid valve 100 and cylinder 46 operative to control the flow of fluid between the cylinder and the pump on the return stroke during which the endless belt conveyor assembly is lowered by gravity.

As best seen in Figure 8 of the drawing, hydraulic line interconnects the output side of pump 54 with threeway valve 106. This valve is spring-biased into a neutral position wherein it interconnects line 110 with line 112 leading to the solenoid valve. Similarly, valve 100 in its deenergized or neutral position interconnects line 112 through line 114 to the exhaust side of the pump. Now, when the first of the two buttons of switch 102 is pressed, the solenoid valve 100 is energized to disconnect line 114 from line 112 and connect the latter to cylinder 46 through line 116 and metering valve 108. Thus, as long as this button of switch 102 is held closed, fluid is delivered to cylinder 46 extending the piston and elevating the conveyor belt assembly 26. As soon as this assembly is elevated to the desired position, release of the button disconnects line 116 and reconnects lines 112 and 114 when the valve 100 returns to neutral. The fluid trapped in line 116 and in cylinder 46 behind the piston will maintain the unit in elevated position. Depressing the other button of switch 102 actuates valve 100 in the other direction, disconnects line 112 from line 116 and connects the latter with exhaust line 114. Thus, no fluid is supplied to the cylinder from line 112 and the fluid in said cylinder and 1ine,116 is allowed to drain'baek to the pump as the endless belt assembly lowers by gravity retracting piston 48. Obviously, valve 108 controls the rate of return of fluid to the pump thus regulating the rate of descent of the conveyor assembly.

Figures 2 and 3 show that three-way valve 106 that controls the hydraulic brakes is actuated by foot'pedals 118 mounted on a common shaft 120 for rockable movement on the front end of the carriage within easy access to the operator. Crank arm 122 and link 124 operatively interconnect the shaft 120 with valve 106.. As aforementioned, valve 106 is spring-biased into the neutral position wherein line 110 and 112 are interconnected while line.126 leading from valve 106 to. the brakes is shut ofi.

Again referring to Figure 8, depressing one ofthe foot ape-1,831

pedals 113 causes shaft 120to rotate actuating-valved so that line 126 is connected to line 110 and line'112is shut oif. This position of valve 106 pressurizes accumulator 104 and sets the brakes. Release of the foot pedal to place valve 106 again in neutral position, shuts off line 126 trapping the fluid therein and in the accumulatonso that the brakes remain set. To releasethe brakes, foot pedals 118 are raised to turn shaft 120 in the opposite direction thus disconnecting line 110 and interconnecting lines 126 and 112 so that fluid can return to the pump through line 114 when valve 190 is in neutral position.

It should also be mentioned that the preferred embodi- .ment of the swivel stacker of the present invention includes a control 128 electrically connected to a reversible motor (not shown) used to move the spring belt conveyor 12. This motor is operative to move the spring belt conveyor either forward or backward and by controlling its movements from the front end of the stacker 10, it becomes possible to accomplish a shuttle action of the conveyor-stacker assembly that is very useful in shifting its position relative to various stacks and rows of packaged materials.

Having thus described the several useful and novel features of the swivel stacker of the present invention, it

i will be seen that the many worthwhile objectives for which it was designed have been achieved. Although but a single specific embodiment of the invention has been illustrated and described in connection with the accompanying drawings, I realize that certain changes and modifications therein may be made by those skilled in the art within the broad teaching hereof; hence, it is my intention that the scope of protection afforded hereby shall be limited only insofar as said limitations are expressly set forth in the appended claims.

What is claimed is:

1. A swivel stacker of the type particularly suited for use in unloading filled bags and the like from a conveyor, a carriage including a bedframe and an upright frame depending from the rear end thereof, a pair of casters supporting the front end of the bedframe, a fixed brake element depending from the rear end of the bedframe, a movable brake element mounted on the fixed brake element for relative rotation about a substantially vertical axis, a friction element depending from the fixed brake element for movement upon actuation into engagement with the movable brake element to prevent relative rotation therebetween, actuating means operatively connected to the friction element adapted to set and release the brakes, at least one caster mounted on the movable brake element supporting the rear end of the bedframe, an endless belt conveyor assembly including a conveyor frame with the rear end thereof mounted on the upper end of the upright frame for tiltable movement about a transverse substantially horizontal axis, a drive roller'and at least one driven roller journalled for rotation in longitudinally spaced substantially parallel relation transversely of the conveyor frame, an endless belt operatively interconnecting the drive and driven rollers, drive means carried by the conveyor frame and operatively connected to the drive roller for rotating same to move the endless belt, a hydraulic cylinder and piston interconnecting the carriage with the conveyor assembly at a point spaced forward of the rear thereof, a power-driven hydraulic pump connected to the hydraulic cylinder operative upon actuation to extend the piston and elevate the conveyor assembly, and control means connected to the hydraulic pump operative to actuate same and extend or retract the piston.

2. The swivel stacker as set forth in claim 1 in which the movable brake element comprises a drum and the friction element comprises at least one brake shoe movable into contact with said drum.

3. The swivel stacker as set forth in claim 1 in which rigid attachment means depend from the movable brake element adapted for eonnectionto a fixed support to hold said element while the carriage and conveyorassembly are free to swing from .side-to-side relative .thereto with the brakes released.

4. The swivel sta'ckeras set. forth in claim lrin which the actuating means includes a three-way valve con- :nected between the inlet .androutlet sides of the pump, and an accumulator connected between the pump and friction element, the valve being operative in one position to disconnect the accumulator from the pump while interconnecting the inlet and outlet sides thereof, said valve being operative in a second position to interconnect the outlet side of the pump with the accumulator and disconnect the inlet side therefrom, and said valve being operative in a third position to interconnect the inlet side of the pump with the accumulator while disconnecting the outlet side therefrom.

5. The swivel stacker as set forth in claim 1 in which the control means comprises a three-way valve connected between the inlet and outlet sides of the pump and with the hydraulic cylinder in 'a manner to extend the piston, the valve having a first position in which the cylinder is disconnected while the inlet and outlet sides of the pump are interconnected, said valve having a second position wherein the cylinder and outlet side of the pump are interconnected and the inlet side is disconnected, and said valve having a third position wherein the cylinder and inlet side of the pump are interconnected while the outlet side is disconnected therefrom.

6. The swivel stacker as set forth in claim 4 in which the control means comprises a second three-way valve connected between the inlet and outlet sides of the pump and with the hydraulic cylinder in a manner to extend the piston, the second valve having a first position in which the cylinder is disconnected while the inlet and outlet sides of the pump are interconnected, said second valve having a second position wherein the cylinder and outlet sides of the pump are interconnected and the inlet side is disconnected, and said second valve having a third position wherein the cylinder and inlet side of the pump are interconnected while the outlet side is disconnected therefrom.

7. The swivel stacker as set forth in claim 4 in which foot-pedal means are operatively connected to the valve for actuating same, and means are included within the valve operative to' normally maintain same in first position.

8. The swivel stacker as set forth in claim 4 in which the movable brake element comprises a drum and the friction element comprises at least one brake shoe movable into contact with said drum.

9. The swivel stacker as set forth in claim 4 in which rigid attachment means depend from the movable brake element adapted for connection to a fixed support to hold said element while the carriage and conveyor assembly are free to swing from side-to-side relative thereto with the brakes released.

10. The swivel stacker as set forth in claim 5 in which 7 the three-way valve comprises a double-acting solenoid valve normally biased into first position.

11. The swivel stacker as set forth in claim 5 in which means comprising a metering valve is connected between the three-way valve and the cylinder.

12. The swivel stacker as set forth in claim 5 in which the movable brake element comprises a drum and the friction element comprises at least one brake shoe movable into contact with said drum.

13. The swivel stacker as set forth in claim 5 in which rigid attachment means depend from the movable brake element adapted for connection to a fixed support to hold said element while the carriage and conveyor assembly are free to swing from side-to-side relative thereto with the brakes released.

14. The swivel stacker as set forth in claim 6 in which foot-pedal means are operatively connected to the first three-way valve, for actuating same, and means. are in- 'cluded within said first three-way valve operative to nor- :rnally maintainsame infirst position. r'

l5. The swivel stacker as set forth in'claimfi in which the second three-way valve comprises a double-acting solenoid valve normally biased into first position.

16; The swivel stacker as set forth in claim' 6 in which '8 'means' comprisingra metering valve is connected between the three-way valve and the cylinder.

H V i References Cited in the file of this patent 7 UNITED STATES PATENTS 2,596,265 Manierre May13,1 952 2,796,999 Russell June 25, 1957 

